1. Field of the Invention
This invention relates to a process of severing and subsequently stacking web sections which in their central portions are provided with locating holes and preferably consist of double bags which have been severed from a tubular or semitubular, continuous plastic film web and are closed by hot-wire welding and have opening-defining edges, in which process the web sections are delivered by a delivering means preferably consisting of a so-called wicketer having pairs of inner and outer wicketer arms, which are arranged in a starlike array and rotate about a horizontal axis, and the web sections are deposited by the delivering means in a stacking station onto a stacking conveyor, which consists of endless tensile elements, which are trained around reversing pulleys or rollers and are intermittently driven and provided with upstanding stacking pins, the stacks formed by the web sections placed on the stacking pins are intermittently carried off by an intermittent advance of the tensile elements, and the web sections or the tubular or semitubular continuous web have or has been perforated on or adjacent to the longitudinal center line of each section or of the web.
The invention relates also to apparatus for carrying out the process described first hereinbefore, comprising a so-called wicketer, which in each of a plurality of parallel planes which are at right angles to and contain the axis of rotation of the wicketer which comprises four wicketer arms forming a star-shaped array, wherein the star-shaped arrays formed by the inner wicketer arms extending in the two innermost ones of the planes define a gap between them.
2. Description of the Prior Art
In a process which is known from Published German Application No. 31 38 221, the double bags which have been severed from a tubular web and closed by transverse seam welds are deposited on stacking plates, which are carried by endless chains and are provided with two rows of stacking pins on respective sides of their longitudinal center plane. The stacking pins serve to receive the bags. The stacks of bags are separated by a heated cutter, which is adapted to be lifted and lowered and by which the stacks disposed in the stacking station are severed between the rows of stacking pins in an operation in which the stacking plate constitutes an abutment cooperating with the cutter. As the stacking plates constitute the abutments for the heated cutters, the plates must be relatively large and heavy. For this reason the known apparatus is relatively expensive because the endless chains must be provided with stacking plates which have the same spacing as the stacks to be transported by the plates and which must be adapted to act as abutment plates for cooperation with the cutter. In the process that has been described with reference to FIG. 5 of Published German Application No. 31 38 221 the locating holes are disposed in a central strip-shaped central area, which is laterally defined by perforation lines and which is bisected by the cut performed to cut the stacks apart.
Published German Application No. 22 44 495 discloses stacks which consist of double bags which are held together only by a central perforation line and which are blocked to each other by hole-defining seam welds adjacent to said perforation lines. The double bags are not separated from each other before they are stacked but only as they are torn from the stack of double bags.
Published German Application No. 30 49 142 discloses a process of making bags, which are joined by perforation lines from a two-ply web, in which the bags are joined by perforation lines and from which pairs of bags are torn when they have been made. Grippers which laterally grip each pair of bags to be torn off are provided for tearing each pair of still connected bags from the web and for stacking said pairs of bags. Said grippers are secured to the ends of spokelike arms, which are arranged in pairs and mounted on rotatably mounted hubs, which are operatively connected to drive means. In that known apparatus each pair of still connected bags are torn off by grippers which are mounted on revolving arms. But the still connected bags of each pair are not separated once more as they are transferred from the web onto the stack.